App turns smartphone into drug-dose calculator

TORONTO - Figuring out the proper dose of liquid fever medication for a young child can be trying for parents when doctors prescribe in milligrams and the bottle comes in millilitres.

But a Toronto pediatrician and two self-described computer techies hope to soon have an app for that: an easy-to-use dose calculator for smartphones aimed at preventing a child getting too little — or worse — too much of a drug.

"In pediatrics, the most common reason parents bring their children to see a doctor is because they have a fever," says Dr. Niraj Mistry. "It's the most concerning symptom that parents notice in their kids."

Usually the fever is caused by a viral infection, so doctors typically prescribe an over-the-counter child-strength medication such as acetaminophen or ibuprofen to bring down their temperature.

"Those are really the only medications that you can give for children under six because recently Canada and U.S. regulatory bodies banned all cough and cold medicines for kids under six," says Mistry.

The problem for parents is that doctors prescribe in milligrams based on a child's weight, while fever medicines for young kids are sold in liquid form and measured in millilitres, he says.

As well, package directions may recommend a dosage based on an age range — for instance, a certain amount for children aged four months to one year, says Mistry.

"The problem is a four-month-old weighs, let's say, six kilograms and a one-year-old weighs 10 kilograms, so the dosing range for that is very broad if you base it on their weight."

And trying to quickly convert milligrams into millilitres can be challenging for parents dealing with a sick and often fussy child, he says.

In one case reported in the Canadian Medical Association Journal, a doctor had prescribed 10 milligrams of acetaminophen for a child with a fever. The bottle contained 24 millilitres of liquid medicine and the parents mistakenly gave the child 10 millilitres bases on the prescribed number — or almost half the bottle.

The child had to be monitored for liver failure due to drug toxicity, but ultimately recovered, he says, adding that "unintentional overdosing of Tylenol is the most commonly known reason for liver failure in children."

So when Mistry signed up for a graduate class at the University of Toronto designed to bring together students from all disciplines to create mobile phone apps to deal with real-world problems, he wanted to find a way to solve the dose discrepancy issue in liquid fever meds.

In the parlance of the class, Mistry was the "apper" — the person who came with the issue to be solved. He teamed up with two experienced computer programmers, Pooja Viswanathan and David Xue, who both work in the Intelligent Assistive Systems Technology lab at Toronto Rehab Institute.

"Niraj came to us with the problem and David and I sat down and said: 'OK, how can we actually design this app and how can we get the data that we need," Viswanathan recalls.

The trio came up with a prototype mobile phone app that they dubbed Snap'N'Dose, which they plan to refine, test out in a study with doctors and parents, then hopefully bring to market within a year.

Their solution is simple to use: parents snap a photo of the drug identification number, or DIN, found on the packaging of all prescription and over-the-counter medications sold in Canada, which are listed in a Health Canada database that provides ingredient, dosage and other information.

Snap-N'Dose then calculates the proper dose based on a product's measurement — such as liquid millilitres — based on a child's weight and age. It can also send a reminder when the next dose should be administered and the warn of the maximum dose per day.

"There really is a problem in terms of communicating in a simple way what a parent needs to do when a child falls sick," Viswanathan says. "When it's really stressful when your child is sick and potentially crying and you need to quickly administer that dose ... the exact amount of dose that the parent needs to give the child is not (easily) accessible. And it's quite crucial."

As well, there are a number of different brands of fever medicines, and each has its own measurement and dosage recommendations, she points out.

Xue says the study the group is planning will look at whether using Snap'N'Dose is superior in helping parents determine the correct dose for their child compared with parents who don't use the app.

Jonathan Rose, a professor of electrical and computer engineering who runs the course, said he's delighted the three post-doctoral students came up with an app that offers such a user-friendly solution for an everyday problem.

"I think it's a great app and it was a wonderful collaboration between a doctor and the computer scientists to do something new and right on point," he says. "Pooja and Niraj and David are really keen to keep doing this. They're really excited by all that's possible in this."

Mistry says that if parents and caregivers are more comfortable with giving their child the correct dose of an over-the-counter medication, it can be empowering for them but also improve child health overall.

"So this is definitely a way to help that," he says. "It's a really simple app solving a potentially serious problem.

"And it's amazing the capability of phones. They're not just phones anymore — they're computers in your hand that can really change the way health care is delivered."